Bangladeshi military officials say troops have uncovered a mass grave believed to hold the bodies of at least 66 officers killed by mutinous border guards in Dhaka this week.

Officials say troops found dozens of bodies as they searched the guards' headquarters, where the bloody two-day revolt unfolded.

Military officials say the dead body of the commander of the Bangladesh Rifles border guards, Major General Shakil Ahmed, was found inside the compound.

Hundreds of border guards fled after giving up their weapons on Thursday.

In a dramatic scene Friday, onlookers stood by as military tanks rolled into the compound unchallenged, and police and soldiers began surveying the carnage left behind. Scores of guard officers remain missing.

Prime Minister Shiekh Hasina sent military tanks throughout Dhaka to help calm the situation.

Bangladeshi authorities have arrested at least 300 border guards who allegedly took part in the mutiny.

The rebel guards laid down their weapons after the prime minister vowed to look into their grievances, which include demands for better pay.

Tensions have long been simmering among the Bangladeshi border guards, who complain they are treated like second-class citizens by the country's military. The guards' main job is to patrol the country's borders, but they also can serve as a backup for the army and police.